Heat interchanger



March 8, 1955 c. s. SIMPELAAR I 2,703,700

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' HEAT INTERCHANGER Filed Nov. 22, 1950 5 Sheets-Sheet 5 L CZ dejfim eZczczr 7 L J f v United States Patent HEAT INTERCHANGER Clyde S. Simpelaar, Racine, Wis., assignor to Modine Manufacturing Company, Racine, Wis., a corporation of Wisconsin Application November 22, 1950, Serial No. 197,127

25 Claims. (Cl...257--245) The invention relates generally to heat exchange structures, and more particularly to a structure which is adapted for use as an interchanger in solvent recovery and similar operations.

The present invention is particularly directed to a structure for the removal of one material from another, or the addition of one to another, wherein the control of temperature conditions may either be critical to or greatly facilitate efficient operations. The invention is thus especially applicable to operations such as the condensation of a solvent or other vapor from a gas containing the same, the vaporizing of a liquid for the purpose of saturating a gas, and scrubbing and absorptive operations for the removal of an undesirable constituent of a gas by absorption in a liquid, or the addition of a desirable constituent to a liquid by its removal from a gas. It is believed apparent that in performance of such operations, while the structure is, in effect, a heat exchanger requiring highly eflicient heat transfer surface, the flow conditions of the liquid or condensate therein is of importance, and the present invention therefore contemplates the use of novel means for providing flow conditions which will promote highly eflicient operation. Likewise, desirable flow conditions in respective operations above mentioned will vary considerably, and the physical requirements to satisfactorily serve one condition may be more or less opposite to that of another condition.

The invention has therefore among its objects the production of a heat exchange structure which is particularly adapted for use in solvent recovery systems, vaporizing operations, absorbing and scrubbing operations resulting in high efficiency in the performance of such operations. 7

Another object of the invention is the production of such a heat exchange structure employing a large heat transfer surface area, with a minimum in size and bulk in which such surface is designed to provide predetermined flow conditions over such surfaces.

A further object of the invention is the production of a novel shaped heat transfer surface which is so designed that good efliciency is obtained under varying conditions. As above mentioned, the function of the heat transfer surface may vary considerably and may even be somewhat opposed, in view of which the design should provide efficient action in all cases. An example of the above is in connection with a case of scrubbing and absorbing, wherein it may be desirable to have the condensate or liquid in the structure flow away from the center of the fin elements to the side walls, whereas in solvent recovery, or the like, which in effect constitutes a fractional distillation process, it is desirable to have the liquid flow to the center of the fin to achieve re-evaporation and a reflex action.

A further object of the invention is the production of such a structure having a novel means for the removal of liquid at different steps in the operations.

A further object of the invention is the production of a novel fin structure, including means for accurately spacing the fin elements, and novel means for achieving longitudinal registration between such fin elements.

Many other objects and advantages of the construction herein shown and described will be obvious to those skilled in the art from the disclosure herein given.

To this end my invention consists in the novel construction, arrangement, and combination of parts herein shown and described, and more particularly pointed out in the claims.

2,703,700 Patented Mar. 8, 1955 In the drawings, wherein like reference characters indicate like or corresponding parts:

Fig. l is a side elevational view of an interchanger embodying the present invention particularly adapted for use in solvent recovery process, or the like, with portions of the interchanger broken away;

Fig. 2 is an elevational view in section of portions of the structure illustrated in Fig. 1.

Fig. 3 is a side elevational view with portions in section taken approximately on the line 33 of Fig. 2;

Fig. 4 is a top plan view with a portion of the structure in section taken approximately on the line 4-4 of Fig. 2;

Fig. 5 is a sectional view taken approximately on the line 5-5 of Fig. 2;

Fig. 6 is a sectional view taken approximately on the line 66 of Fig. 5;

Fig. 7 is an end elevational view of one of the gutters illustrated in Figs. 5 and 6;

Fig. 8 is a perspective view of the end portion of one of the gutters;

Fig. 9 is a perspective view of a portion of the exchange structure disclosing the fin arrangement in the respective passes;

Fig. 10 is an end elevational view of one of the fin sections employed in the gas passes;

Fig. 11 is an elevational view of such fin structure;

Fig. 12 is a sectional view taken approximately on the line 12-42 of Fig. 11;

Fig. 13 is a perspective view of a portion of a fin elerinent such as that illustrated in Figs. 10 through 12; an

Fig. 14 is a perspective view of a portion of one of the plenum elements employed in the liquid passes.

The present invention may be readily embodied in structures of the type shown and described in my c0- pending application, Serial No. 780,251, filed October 16, 1947, now U. S. Patent 2,606,007, granted August 5, 1952, utilizing channel-shaped fin elements arranged in a series of slabs to form a plurality of fluid passes in heat transfer relation. As disclosed in such application, the edges of the slabs may be enclosed by suitable members, and metal sheets may be interposed between the respective slabs, suitable means being provided for the ingress and egress of fluid to and from the respective passes. The efficiency, simplicity, compactness, and durability of such construction renders it most suitable for the practice of the present invention which, as illustrated and described herein, embodies such general construction.

The present invention contemplates the use of vertically extending fluid passages, one series of passages being adapted to receive a gas and a liquid, and the other a fluid for maintaining the temperatures in the gas passages within predetermined limits. The gas passes are provided with a plurality of vertically extending heat transfer surfaces which are designed to direct the flow of liquid over such surfaces in predetermined directions; to wit, toward the center of such surfaces, or toward the outer edges thereof, depending upon the desired function of the structure. Novel means is also provided for withdrawing liquid from the structure at Y aigious levels for use in distillation processes and the Referring to the drawings, and more particularly to Figs. 1 through 5, 1 indicates generally an interchanger for use in solvent recovery, or other distillation processes, having a plurality of vertically extending gas passages or passes 2, between which are interposed respective fluid or liquid passes 3, the gas passes being separated from the liquid pass by separator sheets 4, and the end passes having outer cover sheets 5. The side edges of the respective gas and liquid passes are each closed by respective members 6 and 6' which, in the embodiment of the invention, are illustrated as being channel-shaped. Positioned in the gas passes are -a plurality of vertically extending, channel-shaped fin elements 7, and positioned in the liquid passes are a plurality of vertically extending, channel-shaped fin elements 8. The structure thus far described is generally similar to that illustrated in my copending application heretofore referred to, each of the fin elements 7 in the gas passes comprising a pair of side walls 9 connected by an intermediate cross wall 10, with the side walls 9 extending in parallel relation in the same direction with respect to the cross wall 10. As clearly illustrated in Figs. 10 and 13, the side walls 9 are each outwardly offset at 11 to form parallelly extending edge portions, with the distance of the offset 11 being approximately equal to the thickness of the metal employed in the fin element, and as clearly illustrated in Fig. 9, the fin elements 7 are assembled in nested relation with the offset portions 12 of the side walls overlapping the preceding fin element.

As illustrated in Fig. 11, the cross wall 10 of each fin element 7 is provided with a plurality of diagonally extending deformations 13a and 13b symmetrically arranged with respect to the center line of the cross wall 11. In the embodiment of the invention illustrated, the deformations 13a and 13b are produced by forming a plurality of slits 14a and 14b in the cross wall, and deforming the metal of the latter at the slits, as clearly illustrated in Figs. 10, 11, and 12, with the louvers thus formed on opposite sides of the cross wall center line being inclined toward the latter. The free edges of the louvers or deflectors at one side of the center line are positioned at the bottom of each respective louver, as viewed in Fig. 11, and those on the opposite side having their free edges positioned at the top thereof. With this construction, liquid flowing downward on the surface of the cross wall 10 will be directed toward the center of the latter and, at the same time, in the embodiment of the invention illustrated, will tend to equalize on the opposite surfaces of the cross wall. If it is desired to direct the fluid on the cross wall surface to the outer edges thereof and the side walls 9, the fin elements are assembled in an inverted position to that illustrated in Fig. 11, whereby the portions 13a and 13b will direct the liquid to the outer edge of the cross wall. Likewise, one end of each fin element 7 is formed with a concave arcuate edge 15a, and the opposite end is formed with a convex arcuate edge 15b, with the curvatures of the respective edges being complementary to one another so that the portions of the respective edges 15a and 15b at each side of the fin centerline extend angularly relative to the latter in the same direction as the corrsponding deflectors 13a and 13b, whereby liquid at such edges is directed in the same direction as liquid at the deflectors. Thus the structure illustrated in Fig. 11 will function substantially equally well in directing fluid to either the center or the side edges of the cross wall, as may be desired in the particular application.

Positioned at the ends of the gas passes are channelshaped members 16, each having a plurality of apertures 17 therein for the admission and exit of fluid to and from such passes. Both ends of the liquid passes are each closed by solid, channel-shaped members 18, and positioned adjacent the closure members 18 at each end of the liquid passes are a plurality of channel-shaped plenum elements 19 generally constructed similar to the fin elements 7 and having a plurality of apertures 19 therein, with the plenum elements being positioned horizontally, as clearly illustrated in Figs. 2 and 3. The gas passes may be operatively connected to a supply duct 21 and outlet duct 22 by suitable plenum shells 23 and 23', respectively, secured to the interchanger by bonding, or other suitable means, as indicated at 24. The liquid passes in the embodiment of the invention illustrated are connected to a liquid supply line 25 and exhaust line 26 by suitable manifolds, indicated generally by the numeral 27, each of the latter comprising a horizontally extending tubular member 28 operatively connected to the respective lines 25 and 26, from each of which members extends a plurality of tubular members 29, the latter, in the construction illustrated, being cylindrical at the end thereof secured to the member 28, and at their opposite ends are transversely elongated, as indicated at 31, whereby they may be inserted in similar elongated openings in the respective channel members 6 of the liquid passes at the ends of the plenum elements 18, whereby liquid may flow from the line 25 into the member 28, through the respective members 29 into the top of the liquid passes, and out from the same through the lower manifold 27 into the exhaust line 26, with the plenum elements being operative to effectively distribute the liquid through each respective liquid pass.

As previously mentioned, the present invention is particularly adapted for use in solvent recovery operations, and as such an operation is a fractional distillation process, novel means is provided for drawing off liquid at different vertical locations in the unit, whereby liquids of various degrees of purity can be obtained. The structure for obtaining these results is illustrated in Figs. 1 through 3, and 5 through 8.

Referring to Figs. 1 and 2, it Will be noted that the fin elements 7 in each gas pass are arranged in slabs vertically spaced from one another to provide intermediate spaces or chambers 32, and a lower chamber 33 adjacent the bottom of the device. Positioned in each of the chambers thus formed are a pair of gutter members 34 and 35, which are generally similar in structure but reversely shaped, each being provided with a base portion 36, and are outwardly offset intermediate of their edges, as indicated at 37, to form a ledge or shoulder with a side wall portion 38 extending upwardly therefrom. As clearly illustrated in Figs. 2, 5, and 6, each pair of members 34 and 35 is positioned in a respective chamber 32, with the base portions 36 suitably bonded or otherwise secured to respective side plates 4, whereby the latter, the ledge positions 37, and side walls 38 form channels for the reception of liquid. Each pair of gutters is inclined, as illustrated in Fig. 2, and secured to the side channel members adjacent the lower ends of each pair of gutter members is a tubular duct 39, with the corresponding ducts from each pass being operatively connected by a tubular manifold member 41 having a suitable connection 42 adapted to be connected into a liquid return line. The side walls 38 of the gutter members 34 and 35 are offset toward one another adjacent the lower ends thereof, as indicated at 43, whereby the extreme end portions 44 of the side walls are positioned in abutting relation, with the ends of the ledge portions 37 and base portions 36 being cut away as indicated at 45, whereby the portions 44 may extend into the adjacent open end of the duct 39. The proportions of the end portions of the gutter structures are such that in the finished device the lower end edges of the gutter members adjacent the cut-away portion 45 will butt against the surrounding structure, and when bonded thereto, will form a substantially fluid-tight channel operative to direct liquid passing down the adjacent surface of the side plates 4 into the channel, and conduct the liquid into the duct 39 and manifold 41.

The structure above described may be assembled in the following manner: The respective passes may be successively assembled in horizontal planes beginning with an outer side plate, upon which is assembled the channel-shaped edge members. The fin members are preassembled into slabs, and the latter, together with the plenum sections, are inserted between the border frame member, over which is placed a separator sheet 4. The next pass is then built up in like manner and, if required, the gutter members are also included. To maintain the pairs of gutter members in proper position until the bonding operation is completed, U-shaped spring members 46 may be provided, having an intermediate portion 47 hearing against the base portion of one of the gutter members, and a pair of leg portions 48 bearing against the base portion of the other gutter member, the portions 47 and 48 being connected by transverse, intermediate portions 49. Following assembly of the second pass, another intermediate sheet 4 is laid over the same, and the next pass assembled in similar manner, succeeding passes being likewise added until a structure embodying the desired number of liquid and gas passes is produced. Suitable bonding material may be incorporated in the assembled structure by any desired means, as for example, inteiposing sheets of bonding material adjacent the intermediate plates 4, suitably coating all or certain elements of the structure prior to assembly with bonding material, or a combination of both, etc. The liquid inlet ducts 29 and ducts 39 are then properly positioned on the structure, and maintained by any suitable means in such position during the bonding operation. Heat is then applied to the assembled structure by suitable means under controlled conditions to bond all the elements of this structure into an integral, unitary assembly. In some cases it may also be desirable to bond the ducts 23 and 23 to the structure in the same bonding operation.

It will be appreciated that as the present invention is particularly adapted for use in fractional distillation process, and the like, and as the structure contains a plurality of similar passes through which the distillation is accomplished, uniformity of operating characteristics, and thus, 1n effect, uniformity of physical structure is particularly desirable to achieve efficient operation of the device. In this connection, it will be apparent that it is therefore desirable that the corresponding slabs of fin members 7 in the respective gas passes be as uniform as possible within practical limitations, in view of which it is particularly desirable to insure proper positioning and spacing between fin elements and identical performance of each unit. vide novel means for properly aligning each fin element with the adjacent fin element, both with respect to the distance between the cross walls of the fin elements, and the longitudinal relation of one fin element to the next. It will also be obvious that the provision of such means allows greater tolerance in manufacturing, and facilitates ready and economical assembly to provide a structure having uniform fiow rates through the corresponding portions of the device. Similarly, as structures such as that illustrated in Figs. 1 and 2 are often employed in groups connected in parallel, it is particularly desirable not only that corresponding elements of the unit be uniform, but also that individual units have uniform operating characteristics.

The means for achieving uniform spacing of adjacent fin elements and the means for achieving longitudinal registration thereof are illustrated in Figs. 10 through 12. Accurate spacing is achieved by forming longitudinal slits 51 at spaced points along the oifsetll of each fin element, and deforming the metal of the side walls 9 adjacent the slit inwardly to form a generally conicalshaped projection 52, the base edge 53 of which, formed by the severing of the material at the slit 51, lies in a plane containing the oifsets 11. As the material comprising the fin members is normally of relatively very light gauge, as for example, four or five thousandths of an inch, and the offset 11, as previously mentioned, is substantially equal to the thickness of the metal to provide efficient nesting of the fin elements, the side walls of the fin elements may be spread during assembly a sufficient distance to permit positioning of the succeeding fin element between the side wall portions 9 of the preceding fin element. However, by providing a stop or ledge, such as the projections 52, of considerably greater size than the thickness of the metal, the fin elements may be readily and accurately nested one within the other. It will be noted with respect to the spaced projections 52 that the novel construction illustrated requires no consideration of staggering the projections 52 on adjacent fin elements, as it is impossible to nest the projections one within the other as the projections do not extend into the cross wall 10.

Longitudinal registration is achieved by providing, at longitudinally spaced points along each fin element, a groove or channel, indicated generally by the numeral 54, in the side walls of each fin element, and as clearly illustrated in Figs. 11 and 13, the portions 55 and 56 of the channel 54 in the side wall 9 and offset portion 12 are so proportioned that the internal surface of the portion 56 is complementary to the external surface of the portion 55, so that when the fin elements are assembled in nested relation and the offset portions 12 overlie the portions 9 of the adjacent fin element, the internal bead formed by the portion 56 may be positioned in the external groove or channed formed by the portion 55 and provide a longitudinal interlock between the fin elements, preventing assembly of the fin elements other than with the fin elements in the desired longitudinal relation.

It will be noted from the above description that I have provided a novel structure particularly adapted for use in systems involving distillation, vaporizing, absorbing, and scrubbing operations, wherein a novel heat transfer surface is employed, together with novel means for obtaining uniformity in corresponding portions of the structure, as well as uniformity in the finished structure whereby a plurality of the same may be employed in parallel relation. Likewise, while I have referred to the passes 3 as liquid passes, it will be apparent that in many applications of the present invention, the passes 3 may carry a gas instead of a liquid, and may employ the cooled gas, from which solvent or other liquid has been condensed, in the gas passes, providing very economical operation.

To achieve these results, I therefore pro- I Having thus described my invention, it is obvious that various immaterial modifications may be made in the same without departing from the spirit of my invention; hence, I do not wish to be understood as limiting myself to the exact form, construction, arrangement, and combination of parts herein shown and described, or uses mentioned.

What I claim as new and desire to secure by Letters Patent is:

1. In a fin structure, the combination of a plurality of channel-shaped fin elements successively nested in the next to form a fluid pass having a plurality of fins extending between opposite side walls, each having a pair of side walls connected by an intermediate wall, said side walls intermediate the height thereof, being outwardly offset to form parallel extending edge portions with the offset substantially equal to the thickness of the material of the fin element, the side walls of the respective fin elements being longitudinally slit at spaced points and deformed inwardly to form a ledge in the plane of the offset engageable with the intermediate wall of the next structure to restrict nesting movement therebetween, said deformations terminating short of the junctures of their respective side wall with the intermediate Wall.

2. In a device of the kind described, the combination of a finned pass comprising a pair of vertically extending, substantially parallel side walls connected by a plurality of spaced, vertically extending fins, each fin having a plurality of projections thereon extending angularly with respect to the vertical centerline of the fin surface and operative to direct liquid on the fin surface in opposite, predetermined directions relative to said centerline, means adjacent the top of the structure for the ingress of fluid therein, means adjacent the bottom of the structure for the egress of fluid therefrom, and means comprising gutter means intermediate the top and bottom of the structure for collecting and withdrawing liquid from such intermediate portion of the pass.

3. in a device of the kind described, the combination of a finned pass comprising a pair of vertically extending, substantially parallel side walls connected by a plurality of spaced, vertically extending fins, each fin having a plurality of projections thereon extending angularly with respect to the vertical centerline of the fin surface and operative to direct liquid on the fin surface in opposite, predetermined directions relative to said center line, said projections being formed by slits in the fin forming louvers, the angularity of the projections being adjacent to said vertical side walls, said projections being alternately staggered and directed inwardly so that the fluid may be directed either to the center or to the side edges of the fin as desired, means adjacent the top of the structure for the ingress of fluid therein, and means adjacent Ehe bottom of the structure for the egress of fluid thererom.

4. In a finned structure, the combination of a plurality of channel-shaped fin elements, each successively nested in the next to form a fluid pass having a plurality of fins extending between opposite side walls, each element having a pair of side walls connected by an intermediate wall, said side walls, intermediate the height thereof, being outwardly offset to form parallel extending edge portions with the offset substantially equal to the thickness of the material of the fin element, the side walls of the respective fin elements having similarly positioned, inwardly extending indentations, the indentations on one fin structure engaging the indentations on the next fin structure to restrict relatively longitudinal movement between said fin structures.

5. In a fin structure, the combination of a plurality of channel-shaped fin elements, each successively nested in the next to form a fluid pass having a plurality of fins extending between opposite side walls, each element having a pair of side walls connected by an intermediate wall, said side walls, intermediate the height thereof, being outwardly offset to form parallel extending edge portions with the offset substantially equal to the thickness of the material of the fin element, the side walls of the respective fin elements having similarly positioned, inwardly extending, complementally formed semi-cylindrical indentations formed on the offset portions, the indentations on one fin structure engaging the indentations on the next fin structure to restrict relatively longitudinal movement between said fin structures.

6. In a fin structure, the combination of a plurality of channel-shaped fin elements successively nested in the next to form a fluid pass having a plurality of fins extending between opposite side walls, each having a pair of side Walls connected by an intermediate wall, said side walls, intermediate the height thereof, being outwardly offset to form parallel extending edge portions with the offset substantially equal to the thickness of the material of the fin element, the side walls of the respective fin elements being longitudinally slit at spaced points at the offset and deformed inwardly to form a ledge engageable with the intermediate wall of the next element to restrict nesting movement therebetween.

7. In a device of the kind described, the combination of a vertically extending hollow structure forming a fluid pass, means adjacent the upper and lower ends of the structure for the ingress and egress of fluid into and from said structure, and a plurality of vertically extending, substantially planar fins connected along their vertical edges to opposite side walls of the pass, said fins having vertically spaced deformations therein, the deformations on each fin extending angularly with respect to the vertical centerline of such fin, said deformations being formed by slits in the fins forming louvers, whereby portions of the deformations on opposite sides of such centerline extend in converging directions relative thereto.

8. In a multiple fluid heat exchanger, the combination of a vertically extending hollow structure forming a fluid pass of the multiple fluid heat exchanger, means adjacent the upper and lower ends of the structure for the ingress and egress of fluid into and from said structure, and a plurality of vertically extending, substantially planar fins connected along their vertical edges to opposite side walls of the pass, said fins having vertically spaced slits therein, the slits on each fin extending angularly with respect to the vertical centerline of such fin, whereby portions of the slits on opposite sides of such centerline extend in converging directions relative thereto, said fins being deformed at a side of each slit out of the plane of the fin forming alternately arranged divergent louvers on opposite sides of the center line, and said louvers converging angularly with respect to the center line.

9. In a multiple fluid heat exchanger, the combination of a vertically extending hollow structure forming a fluid pass of the multiple fluid heat exchanger, means adjacent the upper and lower ends of the structure for the ingress and egress of fluid into and from said structure, and a plurality of vertically extending, substantially planar fins connected along their vertical edges to opposite side Walls of the pass, said fins having vertically spaced slits therein, the slits on each fin extending angularly with respect to the vertical centerline of such fin, whereby portions of the slits on opposite sides of such centerline extend in converging directions relative thereto, said fins being deformed at a side of each slit out of the plane of the fin, certain of said deformations at one side of the centerline being disposed at one corresponding side of the slits associated therewith, and certain deformations at the other side of the centerline being disposed at the opposite corresponding side of the slits associated therewith.

10. As an article of manufacture, a fin structure formed from a strip of relatively thin sheet metal, said strip being bent in the same direction along a pair of longitudinal lines spaced from the edges to form an intermediate wall having oppositely disposed, longitudinally extending side walls, each side wall being offset outwardly intermediate its edges so that the free edge portions thereof are spaced a greater distance apart than the width of said intermediate Wall, with the distance between the inner faces of said offset portions being approximately equal to the distance between the outer faces of the portions of the side walls adjacent said intermediate wall whereby a like fin structure may be positioned between said offset edge portions, the offset edge portions of one of said side walls having a projection extending inwardly from the inner face thereof, and the portion of one of said side walls adjacent the intermediate wall having a recess in the outer surface thereof of a size to receive such a projection on a like fin structure when the offset edge portions of the latter are positioned opposite the side wall portions adjacent said intermediate wall, whereby a plurality of such fin structures may be nested in longitudinally interlocked relation.

11. As an article of manufacture, a fin structure formed from a strip of relatively thin sheet metal, said strip in the same direction along a pair of longibeinz bent tudinal lines spaced from the edges to form an intermediate wall having oppositely disposed, longitudinally extending side walls, each side wall being offset outwardly intermediate its edges so that the free edge portions thereof are spaced a greater distance apart than the width of said intermediate wall, with the distance between the inner faces of said offset portions being approximately equal to the distance between the outer faces of the portions of the side walls adjacent said intermediate wall whereby a like fin structure may be positioned between said o fset edge portions, the offset edge portions of one of said side walls having a semi-cylindrical bead projection extending inwardly from the inner face thereof normal to the plane of said intermediate wall, and the portion of one of said side Walls adjacent the intermediate wall having a semi-cylindrical recess in the outer surface thereof complementary in size and shape to such projection, whereby such a projection on a like fin structure may be positioned in such recess when the offset portions of such like fin structure are positioned opposite said side wall portions adjacent said intermediate portion, and such nested fin structures are longitudinally interlocked.

12. As an article of manufacture, a fin structure formed from a strip of relatively thin sheet metal, said strip being bent in the same direction along a pair of longitudinal lines spaced from the edges to form an intermediate wall having oppositely disposed, longitudinally extending side walls, each side wall being offset outwardly intermediate its edges so that the free edge portions thereof are spaced a greater distance apart than the width of said intermediate wall, with the distance between the inner faces of said offset portions being approximately equal to the distance between the outer faces of the portions of the side walls adjacent said intermediate wall whereby a like fin structure may be positioned between said offset edge portions, the side walls of the respective fin structures being longitudinally slit at spaced points along said offset and deformed inwardly to form a generally triangularly shaped projection, the apex of which is positioned adjacent the intermediate wall and the base of which is formed by an edge of such slit to form an inwardly extending ledge at said offset engageable with the intermediate Wall of the next fin structure to substantially position the intermediate wall of the latter in the plane of said offsets.

13. As an article of manufacture, a fin structure formed from a strip of relatively thin sheet metal, said strip being bent in the same direction along a pair of longitudinal lines spaced from the edges to form an intermediate wall having oppositely disposed, longitudinally extending side walls, each side wall being offset outwardly intermediate its edges so that the free edge portions thereof are spaced a greater distance apart than the width of said intermediate wall, with the distance between the inner faces of said offset portions being approximately equal to the distance between the outer faces of the portions of the side walls adjacent said intermediate wall whereby a like fin structure may be positioned between said offset edge portions, the side walls of the respective fin structures being longitudinally slit at spaced points along said offset and deformed inwardly to form a generally triangularly shaped projection, the apex of which is positioned adjacent the intermediate wall and the base of which is formed by an edge of such slit to form an inwardly extending ledge at said offset engageable with the intermediate wall of the next fin structure to substantially position such intermediate wall in the plane of said offsets, the offset edge portions of one of said side walls having a projection extending inwardly from the inner face thereof, and the portion of one of said side walls adjacent the intermediate wall having a recess in the outer surface thereof of a size to receive such a projection on a like fin structure when the offset portions of the latter are positioned opposite said side wall portions adjacent said intermediate portion, and such nested fin structures are longitudinally interlocked.

14. As an article of manufacture, a channel shaped fin structure formed from a strip of relatively thin sheet metal and having an intermediate portion and side walls offset outwardly intermediate their edges forming offset edge portions, whereby a like fin structure may be positioned between said offset edge portions, the side Walls of the respective fin structures being longitudinally slit at spaced points along said offset and deformed inwardly to form a generally triangularly shaped projection, the apex of which is positioned adjacent the intermediate wall and the base of which is formed by an edge of such slit to form an inwardly extending ledge at said offset engageable with the intermediate wall of the next fin structure to substantially position such intermediate wall in the plane of said oflsets, the offset edge portions of one of said side walls having a projection extending inwardly from the inner face thereof, and the portion of one of said side walls adjacent the intermediate w having a recess in the outer surface thereof of a size to receive such a projection on a like fin structure when the offset portions of the latter are positioned opposite said side wall portions adjacent said intermediate portion, whereby such nested fin structures are longitudinally interlocked, said intermediate wall having vertically spaced deformations therein, the deformations on each side of the longitudinal centerline of said intermediate wall extending angularly with respect to such centerline and portions of the deformation on opposite sides of such centerline extending in converging directions relative thereto, whereby the deformations of similarly formed nested fin structures are aligned as the nested fin structures are longitudinally interlocked.

15. As an article of manufacture, a channel shaped fin structure for a fin slab of a multiple pass heat exchanger formed with alternate fluid passes and formed from a strip of relatively thin sheet metal and having an intermediate portion and longitudinally extending side walls ofiset outwardly intermediate their edges forming offset edge portions, whereby a like fin structure may be positioned between said offset edge portions, said offset edge portions when assembled into a fin slab are adapted to be in contact with the walls of alternate fluid passes of the heat exchanger said intermediate wall having vertically spaced deformations therein formed by vertically spaced slits extending angularly in opposite directions with respect to the center line of the intermediate wall, the deformations on each side of the longitudinal centerline of said intermediate wall extending angularly with respect to such centerline and portions of the deformation on opposite sides of such centerline extending in converging directions relative thereto, whereby said deformations form louvers with the free edge thereof alternately arranged on the bottom and top thereof on opposite sides of the center line, so that in one position of the fin structure when assembled into a slab the deformations are adapted to direct the flow on the intermediate portion to the outer edges thereof and the side walls, and when the fin structure is assembled in an inverted position, the deformations are adapted to direct the fluid in an opposite direction to ward the center of the intermediate portion.

16. In a multiple fluid heat exchanger, the combination of a vertically extending, hollow structure forming a plurality of alternate and intermediate fluid passes, separate means adjacent the upper and lower ends of the structure for the ingress and egress of fluid into and from the alternate passes and into and from the intermediate passes of said structure, a plurality of vertically spaced slabs of fin elements positioned in each of the intermediate passes, each slab forming a plurality of vertically extending fins by the fin element being longitudinally disposed and connected along their vertical edges to opposite side walls of the particular pass, said fins having vertically spaced deformations therein, the

deformation on each fin extending angularly with respect to the vertical centerline of such fin, whereby portions of the deformations on opposite sides of such centerline extend in converging directions relative thereto, a gutter structure positioned in the space between corresponding pairs of adjacent slabs of fin elements in each intermediate pass and secured to the side walls thereof, said gutter structure being pitched with respect to the horizontal, and operative to direct downward flowing liquid flowing on said side walls to a side edge of said pass, said hollow structure having a liquid outlet opening therein communicating with the lower end of said gutter structure.

17. In a multiple heat exchanger, the combination of a vertically extending hollow structure forming a fluid pass, means adjacent the upper and lower ends of the structure for the ingress and egress of fluid into and from said structure, a plurality of vertically spaced slabs of channel shaped fin elements adapted to be nested and positioned in said pass, each slab forming a plurality of vertically extending fins by the fin elements being longitudinally disposed in nested relationship and connected along their vertical edges to opposite side walls of the pass, a pair of oppositely disposed, spaced gutter members positioned in the space between a pair of adjacent slabs of fin elements and secured to the side walls of the pass, said gutter members being pitched in the same direction with respect to the horizontal, and co-operable with said side walls for directing downward flowing liquid on said side walls to a side edge of said pass, said hollow structure having a liquid outlet opening therein communicating with the lower ends of said gutter members, the latter ends extending inwardly in abutting relation, and into such outlet opening.

18. In a multiple fluid heat exchanger, the combination of a vertically extending hollow structure forming a fluid pass, means adjacent the upper and lower ends of the structure for the ingress and egress of fluid into and from said structure, a plurality of vertically spaced slabs of fin elements positioned in said pass, each slab forming a plurality of vertically extending, substantially planar fins by the fin elements being horizontally disposed and connected along their vertical edges to opposite side walls of the pass, a gutter structure positioned in the space between a pair of adjacent slabs of fin elements and secured to the side walls of the pass, said gutter structure being pitched with respect to the horizontal, and operative to direct downward flowing liquid on said side walls to a side edge of said pass, said hollow structure having a liquid outlet opening therein communicating with the lower end of said gutter structure.

19. In a multiple fluid heat exchanger, the combination of a vertically extending hollow structure longitudinally divided into a plurality of straight and vertically extending alternate and intermediate fluid passes, means adjacent the upper and lower ends of the structure for the ingress and egress of fluid into and from intermediate passes of said structure, means for the ingress and egress of fluid into and from the alternate straight passes, and a plurality of vertically-spaced slabs of vertically extending, substantially planar fins positioned in the intermediate passes and connected along their vertical edges to opposite side walls of such passes, said fins having vertically spaced deformations therein said deformations being formed by slits in the fins and defining louvers on each fin extending angularly with respect to the vertical centerline of such fin, whereby portions of the deformations forming louvers on opposite sides of such centerline extend in converging directions relative thereto.

20. The combination with a heat exchange structure comprising a plurality of alternate and intermediate fluid passes, said intermediate fluid passes formed by vertically spaced slabs of fin elements positioned in the intermediate passes forming finned passageways within the slab and providing a chamber beneath each vertically spaced slab within the intermediate passes, of a gutter structure positioned in the space providing the aforesaid chamber between contiguously spaced slabs and secured to the side walls of the intermediate fluid pass, said gutter structure being arranged transversely to the finned passageways of the slabs and comprising symmetrically shaped members adapted to form channels with the side walls for the reception of a liquid, and a central passageway for the flow of fluid between the contiguous slabs of fin elements.

21. The combination with a heat exchange structure comprising a plurality of alternate and intermediate fluid passes, said intermediate fluid passes formed by vertically spaced slabs of fin elements positioned in the intermediate passes forming finned passageways within the slab, a chamber formed beneath each vertically spaced slab within the intermediate passes, of a gutter structure positioned in the space providing the aforesaid chamber between contiguously spaced slabs and secured to the side walls of the intermediate fluid pass, said gutter structure being arranged transversely to the finned passageways of the slabs and comprising symmetrically shaped members adapted to form channels with the side walls for the reception of a liquid, a central passageway for the flow of fluid between the contiguous slabs of fin elements, and said gutter structure being pitched with respect to the horizontal, and operative to direct downward flowing liquid on said side walls to a side edge of said pass.

22. The combination with a heat exchange structure comprising a plurality of alternate and intermediate fluid passes, said intermediate fluid passes formed by a plurality of spaced slabs of fin elements positioned in the intermediate passes forming finned passageways within the slab, a chamber formed beneath each vertically spaced slab within the intermediate passes, of a plurality of gutter structures, each of said gutter structures positioned in the space providing the aforesaid chamber between contiguously spaced slabs and secured to the side walls of the intermediate fluid pass, and each of said gutter structures being arranged transversely to the finned passageways of the slabs and comprising symmetrically shaped members adapted to form channels with the side walls for the reception of a liquid, and a central passageway for the flow of fluid between the contiguous slabs of fin elements.

23. The combination with a heat exchange structure comprising a plurality of alternate and intermediate fluid passes, said intermediate fluid passes formed by vertically spaced slabs of fin elements positioned in the intermediate passes forming finned passageways within the slab, a chamber formed beneath each vertically spaced slab within the intermediate passes, of a gutter structure positioned in the space providing the aforesaid chamber between contiguously spaced slabs and secured to the side walls of the intermediate fluid pass, said gutter structure being arranged transversely to the finned passageways of the slabs and comprising symmetrically shaped members adapted to form channels with the side walls for the reception of a liquid, a central passageway for the flow of fluid between the contiguous slabs of fin elements, and means disposed between said symmetrically shaped members adapted for spacing said members in the assembly of said gutter structure within its intermediate fluid pass.

24. As an article of manufacture, a gutter member adapted to form a gutter structure for a fluid pass of a heat exchange structure having a liquid outlet opening, said gutter structure being symmetrically formed with respect to a longitudinal aXis, said gutter member being symmetrically shaped with respect to the axis of the gutter structure, and comprising a downwardly extending base portion outwardly oflset with respect to an intermediate portion for aflixing the gutter member to a side wall of the fluid pass, said gutter member formed with an upstanding side wall portion providing a channel with the intermediate portion with the gutter member affixed fluid pass, and said upstanding side to the side wall of the wall portion ofiset laterally with respect to the axis of the gutter structure, whereby a passageway is formed between the side wall portions of symmetrically formed gutter members assembled between the side walls of a fluid pass and also fluid channels are symmetrically formed contiguous to opposite side walls to which the gutter members are aflixed.

25. As an article of manufacture, a gutter member adapted to form a gutter structure for a fluid pass of a heat exchange structure having a liquid outlet opening, said gutter structure being symmetrically formed with respect to a longitudinal axis, said gutter member being symmetrically formed with respect to a longitudinal axis, said gutter member being symmetrically shaped with respect to the axis of the gutter structure, and comprising a base portion outwardly offset with respect to an intermediate portion for aflixing the gutter member to a side wall of the fluid pass, said gutter member formed with an upstanding side wall portion providing a channel with the intermediate portion with the gutter member affixed to the side wall of the fluid pass, and said upstanding side wall portion offset laterally with respect to the axis of the gutter structure, and an end of said gutter member formed to extend inwardly and complemental to said outlet opening, whereby upon the gutter members being assembled in abutting relationship, said abutted ends of the gutter structure extend into said liquid outlet opening, and the channels formed by the assembled gutter members communicate with said outlet opening.

References Cited in the file of this patent UNITED STATES PATENTS 900,827 Brown Oct. 13, 1908 1,880,533 Thomas Oct. 4, 1932 1,941,365 Patterson et al. Dec. 26, 1933 2,281,754 Dalzell May 5, 1942 2,516,871 Haugen Aug. 1, 1950 2,549,466 Hoheisel Apr. 17, 1951 2,558,752 Holm July 3, 1951 2,566,310 Burns et al Sept. 4, 1951 FOREIGN PATENTS 96,981 Sweden Oct. 3, 1939 332,455 Great Britain July 24, 1930 628,704 Great Britain Sept. 2, 1949 868,064 France Dec. 15, 1941 

